1. Field of the Invention
The invention relates to a device for force transfer between a chassis frame and a carriage body of a rail vehicle with a plurality of lemniscate links that are connected to the chassis frame via first joints, a yoke with a middle linking point in which a pivot pin of the carriage body is mountable, where the plurality of lemniscate links are connected to the yoke via second joints and form a Z-shaped assembly and where elastically deformable elements are arranged in the first and second joints and in the yoke.
2. Description of the Related Art
As a rule, chassis, also called bogies, of rail vehicles have two wheel sets that are guided on rails and connected to carriage bodies of the rail vehicle. An essential component of a chassis is a chassis frame to which are connected the wheel sets, for example, via a wheel set guide or a primary suspension, the carriage body, for example, via a secondary suspension, and a device for force transfer. Here, the flows of forces between the individual components primarily pass through the chassis frame, which has a longitudinal direction and a transverse direction, where the longitudinal direction points in the direction of travel of the rail vehicle and the transverse direction is normal to the longitudinal direction.
Typically, the devices used for force transfer are plunger spigots or lemniscate links, where the present invention relates to such lemniscate links. Lemniscate links are characterized in that substantially three rods are interconnected in an articulated manner and the two external rods are mounted on a fixed point, with the three rods forming a Z-shaped assembly. Specifically, the two external rods are two lemniscate links that are each mounted on a fixed point in the chassis frame via first joints. The inner rod is formed by a yoke in which, in the operating state, a pivot pin of the carriage body is mounted in a middle linking point and which is connected to the lemniscate links via second joints.
If, during operation, the carriage body is now deflected in the transverse direction or loaded by a transverse force, then the second joints of the lemniscate links move on a circularly arcuate path about the first joints so that the middle linking point and, hence, the pivot pin are displaced approximately parallel to the transverse direction with respect to the chassis frame. It is self-evident, that in this case, the Z-shaped assembly changes such that the two lemniscate links are no longer parallel to one another.
A tractive force resulting from the movement of the rail vehicle and acting on the chassis frame is transferred via the lemniscate links and the yoke between the carriage body and the chassis frame. Here, when traveling in a straight line, a tractive force direction of the tractive force corresponds to the longitudinal direction of the chassis frame, but can, such as when cornering, deviate therefrom in a range of approximately +/−30°.
In order to be able to absorb and cushion impact loads in the tractive force direction under the operating load, such as when accelerating or braking, the joints and yoke comprise elastically deformable elements, such as rubber bushings. However, because in exceptional situations, such as buffer impacts, in which the rail vehicle approaches a stationary object, extremely high loads occur in the tractive force direction, both lemniscate links and the elastic elements have to be greatly over-dimensioned in order to prevent failure. This results, on the one hand, to increased weight due to the bulky design of the lemniscate links or the yoke and, on the other, to impaired riding comfort because the elastic elements are extremely rigid and hence damping of the impacts that occur during operation is reduced.